%0 Journal Article %J J Alzheimers Dis %D 2021 %T APOE4 Copy Number-Dependent Proteomic Changes in the Cerebrospinal Fluid. %A Berger, Miles %A Cooter, Mary %A Roesler, Alexander S %A Chung, Stacey %A Park, John %A Modliszewski, Jennifer L %A VanDusen, Keith W %A Thompson, J Will %A Moseley, Arthur %A Devinney, Michael J %A Smani, Shayan %A Hall, Ashley %A Cai, Victor %A Browndyke, Jeffrey N %A Lutz, Michael W %A Corcoran, David L %K Aged %K Alzheimer Disease %K Apolipoprotein E4 %K Biomarkers %K Chitinase-3-Like Protein 1 %K DNA Copy Number Variations %K Female %K Fructose-Bisphosphate Aldolase %K Humans %K Male %K Proteomics %K Receptors, Immunologic %X

BACKGROUND: APOE4 has been hypothesized to increase Alzheimer's disease risk by increasing neuroinflammation, though the specific neuroinflammatory pathways involved are unclear.

OBJECTIVE: Characterize cerebrospinal fluid (CSF) proteomic changes related to APOE4 copy number.

METHODS: We analyzed targeted proteomic data from ADNI CSF samples using a linear regression model adjusting for age, sex, and APOE4 copy number, and additional linear models also adjusting for AD clinical status or for CSF Aβ, tau, or p-tau levels. False discovery rate was used to correct for multiple comparisons correction.

RESULTS: Increasing APOE4 copy number was associated with a significant decrease in a CRP peptide level across all five models (q < 0.05 for each), and with significant increases in ALDOA, CH3L1 (YKL-40), and FABPH peptide levels (q < 0.05 for each) except when controlling for AD clinical status or neurodegeneration biomarkers (i.e., CSF tau or p-tau). In all models except the one controlling for CSF Aβ levels, though not statistically significant, there was a consistent inverse direction of association between APOE4 copy number and the levels of all 24 peptides from all 8 different complement proteins measured. The odds of this happening by chance for 24 unrelated peptides would be less than 1 in 16 million.

CONCLUSION: Increasing APOE4 copy number was associated with decreased CSF CRP levels across all models, and increased CSF ALDOA, CH3L1, and FABH levels when controlling for CSF Aβ levels. Increased APOE4 copy number may also be associated with decreased CSF complement pathway protein levels, a hypothesis for investigation in future studies.

%B J Alzheimers Dis %V 79 %P 511-530 %8 2021 %G eng %N 2 %1 https://www.ncbi.nlm.nih.gov/pubmed/33337362?dopt=Abstract %R 10.3233/JAD-200747 %0 Journal Article %J J Alzheimers Dis %D 2021 %T Cerebrospinal Fluid Proteome Changes in Older Non-Cardiac Surgical Patients with Postoperative Cognitive Dysfunction. %A VanDusen, Keith W %A Li, Yi-Ju %A Cai, Victor %A Hall, Ashley %A Hiles, Sarah %A Thompson, J Will %A Moseley, M Arthur %A Cooter, Mary %A Acker, Leah %A Levy, Jerrold H %A Ghadimi, Kamrouz %A Quiñones, Quintin J %A Devinney, Michael J %A Chung, Stacey %A Terrando, Niccolò %A Moretti, Eugene W %A Browndyke, Jeffrey N %A Mathew, Joseph P %A Berger, Miles %X

BACKGROUND: Postoperative cognitive dysfunction (POCD), a syndrome of cognitive deficits occurring 1-12 months after surgery primarily in older patients, is associated with poor postoperative outcomes. POCD is hypothesized to result from neuroinflammation; however, the pathways involved remain unclear. Unbiased proteomic analyses have been used to identify neuroinflammatory pathways in multiple neurologic diseases and syndromes but have not yet been applied to POCD.

OBJECTIVE: To utilize unbiased mass spectrometry-based proteomics to identify potential neuroinflammatory pathways underlying POCD.

METHODS: Unbiased LC-MS/MS proteomics was performed on immunodepleted cerebrospinal fluid (CSF) samples obtained before, 24 hours after, and 6 weeks after major non-cardiac surgery in older adults who did (n = 8) or did not develop POCD (n = 6). Linear mixed models were used to select peptides and proteins with intensity differences for pathway analysis.

RESULTS: Mass spectrometry quantified 8,258 peptides from 1,222 proteins in > 50%of patient samples at all three time points. Twelve peptides from 11 proteins showed differences in expression over time between patients with versus withoutPOCD (q < 0.05), including proteins previously implicated in neurodegenerative disease pathophysiology. Additionally, 283 peptides from 182 proteins were identified with trend-level differences (q < 0.25) in expression over time between these groups. Among these, pathway analysis revealed that 50 were from 17 proteins mapping to complement and coagulation pathways (q = 2.44*10-13).

CONCLUSION: These data demonstrate the feasibility of performing unbiased mass spectrometry on perioperative CSF samples to identify pathways associated with POCD. Additionally, they provide hypothesis-generating evidence for CSF complement and coagulation pathway changes in patients with POCD.

%B J Alzheimers Dis %V 80 %P 1281-1297 %8 2021 Apr 06 %G eng %N 3 %1 https://www.ncbi.nlm.nih.gov/pubmed/33682719?dopt=Abstract %R 10.3233/JAD-201544 %0 Journal Article %J J Alzheimers Dis %D 2016 %T The Effect of Propofol Versus Isoflurane Anesthesia on Human Cerebrospinal Fluid Markers of Alzheimer's Disease: Results of a Randomized Trial. %A Berger, Miles %A Nadler, Jacob W %A Friedman, Allan %A McDonagh, David L %A Bennett, Ellen R %A Cooter, Mary %A Qi, Wenjing %A Laskowitz, Daniel T %A Ponnusamy, Vikram %A Newman, Mark F %A Shaw, Leslie M %A Warner, David S %A Mathew, Joseph P %A James, Michael L %X

BACKGROUND: Preclinical studies have found differential effects of isoflurane and propofol on the Alzheimer's disease (AD)-associated markers tau, phosphorylated tau (p-tau) and amyloid-β (Aβ).

OBJECTIVE: We asked whether isoflurane and propofol have differential effects on the tau/Aβ ratio (the primary outcome), and individual AD biomarkers. We also examined whether genetic/intraoperative factors influenced perioperative changes in AD biomarkers.

METHODS: Patients undergoing neurosurgical/otolaryngology procedures requiring lumbar cerebrospinal fluid (CSF) drain placement were prospectively randomized to receive isoflurane (n = 21) or propofol (n = 18) for anesthetic maintenance. We measured perioperative CSF sample AD markers, performed genotyping assays, and examined intraoperative data from the electronic anesthesia record. A repeated measures ANOVA was used to examine changes in AD markers by anesthetic type over time.

RESULTS: The CSF tau/Aβ ratio did not differ between isoflurane- versus propofol-treated patients (p = 1.000). CSF tau/Aβ ratio and tau levels increased 10 and 24 h after drain placement (p = 2.002×10-6 and p = 1.985×10-6, respectively), mean CSF p-tau levels decreased (p = 0.005), and Aβ levels did not change (p = 0.152). There was no interaction between anesthetic treatment and time for any of these biomarkers. None of the examined genetic polymorphisms, including ApoE4, were associated with tau increase (n = 9 polymorphisms, p > 0.05 for all associations).

CONCLUSION: Neurosurgery/otolaryngology procedures are associated with an increase in the CSF tau/Aβ ratio, and this increase was not influenced by anesthetic type. The increased CSF tau/Aβ ratio was largely driven by increases in tau levels. Future work should determine the functional/prognostic significance of these perioperative CSF tau elevations.

%B J Alzheimers Dis %V 52 %P 1299-310 %8 2016 Apr 15 %G eng %N 4 %1 http://www.ncbi.nlm.nih.gov/pubmed/27079717?dopt=Abstract %R 10.3233/JAD-151190